Lapping machines



y 1962 L. DAY IETAL 3,032,937

LAPPING MACHINES Filed May 51, 1960 3 Sheets-Sheet 1 l 9 1'5 5 5 56 59 2% 29 ax i3 45 4 -5 A I 'II 51 B 23 4A 44 29 56 I 14 15 5 H 2 11 I I l2 INVENTORS.

May 8, 1962 DAY ET AL LAPPING MACHINES 3m max A mdw r V H M m R MW K M 5 5 May L .B

y 8, 1962 L. DAY ET AL 3,032,937

LAPPING MACHINES Filed May 31, 1960 3 s s 5 I N V EN TORS- Ln WRE/VCE DA dose/=71 .DoeR/c/r 5ND THUR Jrm THE/R HTTORNEVS- 3,032,937 Patented May 8, 1962- 3,932,937 LAPPING MACHENES Lawrence Day and Joseph Dohrick, Chicago, and Arthur Kay, Evanston, Ill., assignors to pitfire Tool and Miachine Co., Inc., Chicago, llL, a corporation of Illinois Filed May 31, 1960, Ser. No. 32,897 13 Claims. (Cl. 51128) Our invention relates to new and useful improvements in lapping machines.

Lapping machines which are presently known in the prior art and which are in commercial use include a rotatable lap member on which is placed the work to be lapped. Such work is generally placed within a ring which has the characteristic of rotating about its vertical axis by reason of frictional contact with the lap surface, such ring being formed of such material, for example, cast iron, resulting in maintaining the lap surface in condition for lapping the desired surface on the article. Within the ring and upon the work, either directly on the work or upon a compressible pad, is arranged a pressure plate of substantial weight. The purpose and function of such plate is generally to maintain a proper pressure of'the work upon and against the surface of the lap.

In the lapping operation a suction-like attachment re-' sults between the ring and the lap, with the result that undue manual exertion 'is required to lift the pressure plate and ring from contact with the surface of the lap in order to remove the lapped work. The present invention has as a principal object the provision of a simplified and labor saving arrangement for lifting the pressure plate and the ring from the lap surface to a position thereabove whereby both the pressure plate and ring maybe moved in a horizontal plane from a position over the lap to expose the work thereon and thereby enable the operator to remove the lapped work and to replace on the lap surface other work to be lapped.

Another and equally important object of the invention is to provide a lift for a pressure plate and work holding ring whereby when the pressure plate and the ring are arranged in lapping position with respect to the lap, the ring and pressure plate will adjust themselves to the surface of the lap.

Anothe and equally important object of the invention is the provision of a simple arrangement for releasably latching the pressure plate and work holder ring in lapping position with respect to the lap.

A further object of the invention is to provide in a lapping machine a pneumatic lift for each pressure plate and work holder of the machine whereby the lift for each may beindependently operated of the other without interrupting the lapping operation.

Yet another object of the invention is to provide in a lapping machine a pneumatic lift for the pressure plate and work holder ring and in which the pressure of the pressure plate may be varied so as to apply the required degree of pressure upon the work for proper and effective lapping operation.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

FIG. 1 is a perspective view of a lapping machine embodying our invention;

FIG. 2 is a fragmentary part sectional detail view taken substantially on line 2-2 of FIG. 1;

FIG. 3 is a fragmentary view taken substantially on line 3-3 of FIG. 2;

9 l-Id FIG. 4 is a fragmentary sectional detail view taken substantially on line 44 of FIG. 2; FIG. 5 is a fragmentary sectional detail View taken substantially on line 55 of FIG. 2; FIG. 6 is a sectional detail view taken substantially on line 6-6 of FIG. 2;

FIG. 7 is a fragmentary sectional detail view taken substantially on line 77 of FIG. 6.

The several objects of our invention are accomplished by the preferred form of construction shown in the ac-- companying drawings, in which 10 indicates a base. This base provides a cabinet which houses certain parts for operating the lapping machine.

At the upper end portion of the base, there is a table 11 having arranged centrally therein a rotatable lap plate 12 rotated by mechanism (not shown) contained within the base cabinet 10. Extending upwardly from the table 11 at predetermined points concentrically with respect to the lap plate 12 are pneumatic lifts 13. Each of the lifts 13 is of similar construction.

Each pneumatic lift 13 includes a collar 14 having a flange 15 which is secured to the table 11 as at 16. Posi-f tioned in this collar and extending upwardly therefromis a column 17. This column is open at its upper end as at 18. Telescop'ically arranged upon thecol-umn 17 is a sleeve 19. Arranged within the column 17 and secured to the table 11 as at 20 is a pneumatic cylinder 21 having a piston 22 including an integral piston rod 23. Threaded on the upper end portion of the piston rod 23 as at 23 a cap 24 having a reduced portion 25 fitting into the open end of the sleeve 19 and secured thereto as at 26. The

cap 24 by means of a lock nut 24' is secured to the rod 23 so that when the sleeve 19 is rotated axially with respect to the column 17 for the reasons hereinafter set forth the piston 22 and rod 23 will rotate together.

The cylinder 21 has communication with a suitable compressor (not shown) in a manner well known in theart, and the pressure to the cylinder 21 may be con-- trolled by suitable hand-operated valves 27.

Extending laterally from the sleeve 19 is a lift arm 28. This arm may be of any form of construction which includes a collar 29 embracing and forming a part of the sleeve 19 and movable therewith. In the form shown in the drawings, particularly FIG. 2, the outer end portion of the arm 28 provides a channel 30 within which are spaced webs 31 formed integral with the arm. In one of the webs 31 is mounted a fixed bushing 32 through which a stud shaft 33 projects. In the other of the webs 31 there is an opening 34 which rotatably receives the reduced end 35 of a screw shaft 36, the stud shaft 33 being formed as an integral part thereof. The opposite walls 38 of the guide 37 have aligned openings 38' through which the shaft 36 is freely positioned.

A socket 39 is formed within and integral with the guide 37. A shaft 41 has one end portion 42 inserted in the socket 39. Such end portion 42 provides a threaded opening 42 for threaded engagement with the screw shaft 36. The arrangement is such that while the screw shaft 36 is held against longitudinal movement, it is freely rotated by the handle 43, thereby to shift the shaft 41 and its guide 37 relative to the channel 30.

A work holder ring 44 is positioned upon the lap surface 45 of the lap plate 12. Within this Work holder ring the work to be lapped is arranged. Upon the work and within the work holder and either upon a separating pad usually formed of felt or the like, is arranged a pressure plate 46. The felt pad (not shown) compensates for variation in the height of the work so that the pressure from the pressure plate 46 will be evenly distributed upon the work within the work holder.

This pressure plate may be formed of such material as will best serve the purpose. It is attached to the lower end portion of the shaft 41 by a universal connection 47 which may be of any approved construction such as Will permit the pressure plate 46 to rotate about its vertical axis and to have universal movement whereby to permit the pressure plate to adjust or align itself upon the work. Carried by the work holder ring 44 and extending inwardly at predetermined points circumferentially about such ring are fingers 48, which fingers are disposed over the pressure plate 46 as best shown in FIGS. 2 and 6.

The arm 28 and the sleeve. 19 are rotated relative to the column 17, so as to permit the pressure plate and work holder ring, after the latter have been elevated above the lap member 12, to be rotated at least from a position over the work holder as shown at A of FIG. 1 to the position indicated at B in FIG. 1 at one side of the lap member 12.

To latch the arm 28 in position with the pressure plate 46 and work holder ring 44 in lapping position, there is provided in the column 17 a longitudinally extending keyway 49. Formed in the sleeve 19 and collar 29 is an opening Threaded into the outer end of such opening is a hollow bushing 51, the closed end of which has an opening 52 through which is passed a pin 53 carrying on its inner end portion a guide disc 54 from which projects a latch pin 50' engaging the keyway 49. The latch pin 50* is projected in the keyxvay 49 by a spring 54.

A suitable handknob 55 is provided on the pin 53 to facilitate withdrawal of the latch pin 50 from the keyway. A calibrated plate 56 is secured to one of the vertical walls of the arm 28 and cooperates with an indicator 57 secured as at 58 to the guide 37 and movable therewith. By observing the indicator 57 and the plate 56 the operator may determine the relative movement of the Work holder ring and pressure plate with respect to the arm 28.

To complete the invention, we provide each arm 28 with a handle 59 which facilitates rotating the arm 28 for the reasons herein set forth. The pressure of the pressure plate 46 upon the work may be varied by manipulation of the cylinder 22 to slightly elevate the arm 28 to a position which the operator believes will eifect a proper or required pressure of the pressure plate upon the work.

An important feature of our invention is found in the fact that the pressure plate and work holder may be moved entirely from a position from above the lap member, thus to expose the work either for inspection or for removal and/or replacement. In instances, where it is moved for the purpose of permitting inspection of the work, it is significant to note that the work holder and pressure plate may be returned to their exact, origi nal position over the. work.

In operation, the piston 22 is pneumatically moved relative to the cylinder 21. Movement of this piston 22 results in movement of the sleeve 19 upwardly with respect to the column 17. As the sleeve 19 carries the arm 28, the latter will move therewith. The upward movement of the arm 28 will elevate or move upwardly from the lap member 12 the pressure plate 46. When the pressure plate 46 contacts the fingers 48, upward movement will then be imparted to the work holder ring 44. When the Work holder ring and pressure plate have been lifted to a predetermined position above the lap, the operator releases the latch pin 52 from the keyway 49 and rotates the sleeve 19 relative to the column 17, to a position where the work holder and pressure plate are clear of the lap plate 12, thus permitting the operator to have free access over the surface of the lap plate 12 for the reasons hereinbefore stated.

Both the pressure plate 46 and the work holder ring 44 may be simultaneously adjusted transversely of the lap surface 45. This is accomplished by rotating the screw shaft 36 through the operation of the handle 43. Rotation of the screw shaft 36 moves the guide 37 and the 4 shaft 41 relative to the lift arm 28, thus adjusting the position of the pressure plate and work holder ring as desired with respect to the lap surface.

The arrangement for controlling the operation of the pneumatic cylinder may be of any desired arrangement, the essence of the invention residing in the provision of such cylinder for the purposes herein set forth.

Our invention results in the efiective lapping of work with the minimum degree of efiort and time on the part of the operator. It permits replacement and removal of Work from the lap expeditiously. The construction is such as permits economical manufacture, a requirement necessary in the lapping field because of the nature and size of the lapping apparatus.

While we have illustrated and described the preferred form of construction for carrying our invention into effect, this is capable of variation and modification without departing from the spirit of the invention. We, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail ourselves of such variations and modifications as come within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to protect by Letters Patent is:

l. A device for removing a pressure plate and work holder from they lapping surface of a lapping machine comprising a supporting column, a sleeve telescopically mounted on the column for movement longitudinally thereto, means for rotatably connecting said sleeve to said column for axial movement relative to the long axis thereof, a support carried by and movable with the sleeve and extending laterally therefrom, means connecting the pressure plate and work holder to the support for movement therewith, and means for moving said sleeve longitudinally of the column.

2. The device of claim 1 characterized by the inclusion of means for adjusting said connecting means relative to said support.

3. The device of claim 1 characterized by the inclusion of means for releasably latching said sleeve and said support in a predetermined position with respect to each other.

4. The device of claim 1 characterized by the inclusion of means for releasably latching said sleeve and said support in a predetermined position with respect to each other, and means for adjusting said connecting means relative to said support.

5. The device of claim 3 in which said last named means comprises a longitudinally extending keyway formed in said column and a spring-urged latch member carried by the sleeve and engageable in said keyway.

6. The device of claim 4 in which said last named means comprises a longitudinally extending keyway formed in said column and a spring-urged latch member carried by the sleeve and engageable in said keyway.

7. The combination with a lapping machine having a relatively fiat lapping member, a work holder ring removably positioned on the surface of said lapping member, and a pressure plate confined in said ring, of means for lifting said pressure plate relative to the lapping member,

and radially disposed means carried by said ring and dis posed in the path of movement of said pressure plate whereby when the pressure plate has been lifted a predetermined distance above said lapping member, further lifting movement of said pressure plate will be imparted to lift the ring from a position upon the surface of said lapping member.

8. The device of claim 7 in which said lifting means includes means for permitting rotation of said pressure plate and ring in a horizontal plane from said position over said lapping member.

9. The device of claim 7 further characterized by the inclusion of means for adjusting said pressure plate and ring transversely with respect to the surface of said lapping member.

10. The device of claim further characterized by the inclusion of means for adjusting said pressure plate and ring transversely with respect to the surface of said lapping member.

ll. The device of claim 7 further characterized by the inclusion in said lifting means of means for releasably latching said pressure plate and said ring in a predetermined position with respect to said lapping member.

'12. The device of claim 8 further characterized by the inclusion in said lifting means of means for releasably latching said pressure plate and said ring in a predetermined position with respect to said lapping member.

13. A device for removing a pressure plate and Work holder from the lapping surface of a lapping machine comprising a stationary support column carried by the machine adjacent the edge of the lapping surface, a sleeve telescopically mounted on the column for movement longitudinally with respect thereto, a support carried by and movable with said sleeve and extending laterally therefrom, means connecting the pressure plate and work holder to said support for movement therewith, means for moving said sleeve longitudinally of said column, means for adjusting said connecting means longitudinally of said support, means for releasably latching said sleeve and said support in a predetermined position with respect to each other, said last-named means comprising a longitudinally extending keyway in said column and a springurged latch member carried by said sleeve and engageable in said keyway.

References Cited in the file of this patent UNITED STATES PATENTS 2,565,590 Bullard Aug, 28, 1951 

